This invention is an improvement over the invention disclosed in my U.S. Pat. No. 4,143,639 of Mar. No. 13, 1979 entitled Friction Heat Space Heater.
Prior to the invention disclosed in my said patent it had been known to provide what I call "flow through fluid" heaters which usually consisted of a set of discs rotating under power in vertical planes on a horizontal shaft axis, within a housing, the housing having a liquid inlet and a liquid outlet for heating liquid continually flowing therethrough by the friction of one disc on another.
Exemplary of such patents are U.S. Pat. No. 86,270 to Ball of Jan. 26, 1869 wherein the housing contains a rotor and stator with flat vertical interface and horizontal shaft for heating flow through of air. Also U.S. Pat. No. 4,004,553 to Stenstrom of Jan. 25, 1977 wherein a cup shaped rotor has truncated conical interfaces within a correspondingly shaped solid stator and a horizontal shaft for heating flow through of liquid.
An abandoned patent application to Beldimano, U.S. Ser. No. 326,790 published May 11, 1943 discloses a horizontal shaft rotor within a vaned stator for heating flow through liquid, there being oil filling the rotor chamber. U.S. Pat. No. 2,251,344 to Tesch of Aug. 5, 1941 discloses a drum rotating on a horizontal axis between horizontal friction shoes and in a chamber full of oil for heating flow through liquid.
None of the above patents teach inner and outer friction drums mounted to rotate on a vertical axis, all teach the flow through of a fluid and none teach the use of a small, captive, quantity of oil, only slightly filling the annular rotor chamber, to transfer friction heat between members during rotation.
A French Pat. No. 760,213 of Feb. 19, 1934 to Marical, departs from the horizontal shaft, disc type, friction heater concept of the above patents by heating flow through liquid in the space between inner and outer truncated conical members, the inner member being rotatable on a vertical axis.
However, unlike the elongated cylindrical drums of my said patent wherein the inner drum rotates on a vertical axis within the outer drum, there is no captive supply of oil in the annular space of Marical and there is no air chamber, outside the outer member, to heat air as it is circulated through the air chamber.